Die rule and method of forming and mounting the same



April 18, 1967 M D. MARTIN Re. 26,192

DIE RULE AND METHOD OF FORMING AND MOUNTING THE SAME Origina] FiledMarch 27, 1962 2 Sheets-Sheet 1 INVENTOR. MERRILL 0. MART/N ATTORNEYApril 18, M, T|N Re.

DIE RULE AND METHOD OF FORMING AND MOUNTING THE SAME Original FiledMarch 27, 1962 2 Sheets-Sheet 2 JNVENTOR. MERRILL D. MART/N ATTORNEYUnited States Patent Ofi ice Re. 26,192 Reissuecl Apr. 18, 1967 26,192DIE RULE AND METHOD OF FORMING AND MOUNTING THE SAME Merrill D. Martin,2 Mail Court, Oakland, Calif. 94611 Original No. 3,170,358, dated Feb.23, 1965, Ser. No. 182,732, Mar. 27, 1962. Application for reissue Jan.26, 1966, Ser. No. 526,954

18 Claims. (Cl. 83-665) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

Die rules are male dies formed in a contour corresponding to the shapeof the desired cut, and are used mostly for the purpose of cutting,punching or scoring corrugated boxboard or other fibre material forpackaging, the cutting edge of the die rule working through the boxboardto a suitable platen.

An object of this invention is to provide a die rule and mounting forthe same for use on a rotating member of a rotary shear cutter thefeatures of which die rule and mounting greatly simplify and facilitaterepairs and replacements and render the cutting more accurate.

Particularly it is an object of the invention to provide a die rule madeof a flat strip of metal formed into appropriate contour and thenmounted on a primary base which in turn is mounted on a second basewhich latter is adapted to be mounted on the rotary element of a rotaryshear cutter, the said bases conforming in curvature to the surface of acylinder about the axis of rotation of said rotating element, so thatthe first or primary base is quickly and easily demountable.

A further object of this invention is to provide a die rule formed outof a metal strip into suitable contour for the desired cut, an edge ofwhich die rule is formed into a cutting edge, which may be straight orserrated, and the base edge of which is transversely notched so that byapplying heat to the crotches of the notches and forcing the legsbetween the notches together so as to narrow the mouths of therespective notches sequentially, the die rule can be curvedlongitudinally of the strip to conform to the arc of a cylinder aboutthe axis of rotation of a rotary element of a rotary shear cutter;suitable demountable means being provided for mounting the die rule onsaid rotary element.

A further object of the invention is to provide easily demountablemounting means for a die rule which can be quickly mounted on the rotaryelement of a rotary shear cutter yet accurately position and positivelyhold the die rule without creeping or rocking or any relativedisplacement or play.

A further object of the invention is to provide a die rule whichconforms to the shape of the cut and to the curvature of the rotaryelement on which its is mounted and a method and means for forming andmounting the die rule; which are highly advantageous in operation,reduce the expense of replacement and repair, and render the cutting oeration more accurate.

I am aware that some changes may be made in the general arrangements andcombinations of the several devices and parts, as well as in the detailsof the construction thereof without departing from the scope of thepresent invention as set forth in the following specification, and asdefined in the following claims; hence I do not limit my invention tothe exact arrangements and combinations of the said device and parts asdescribed in the said specification, nor do I confine myself to theexact details of the construction of the said parts as illustrated inthe accompanying drawings.

With the foregoing and other objects in view, which will be mademanifest in the following detailed description, reference is had to theaccompanying drawings for the illustrative embodiment of the invention,wherein:

FIG. 1 is a fragmentary perspective view of the strip for the die rule.

FIG. 2 is a perspective view of the straight die rule.

FIG. 3 is an enlarged fragmental view showing the pulling together ofthe edges of the notch for curving the die rule.

FIG. 4 is a perspective view of the radially curved die rule.

FIG. 5 is a fragmental view showing the opposite bending of adjacentlegs of die rule with straight cutting edge.

FIG. 6 is a fragmental perspective view of the die rule with straightcutting edge and legs with split ends.

FIG. 7 is a perspective view of the laminated wood base.

FIG. 8 is a perspective view of the assembled die rule and mounting.

FIG. 9 is a modified view of the assembly of the die rule in a Wood basewith a plug.

FIG. 10 is a fragmental sectional view of the die rule and the mounting,and

FIG. 11 is a partly sectional fragmental view of the die rule andmounting assembled on a rotating element.

The die rule of my invention is made out of a flat metal strip 1, whichhas a longitudinal cutting edge 2 and a longitudinal base edge 3. Thecutting edge 2 may be provided with cutting serrations 4 as shown inFIG. 1, or may be straight, as shown in FIG. 5.

The base edge 3 of the strip 1 is notched transversely as shown in FIG.2 and then the strip 1 is bent into the shape or contour of the desiredcut, for instance into an elongated hole shaped as shown in FIG. 2.

When this die rule is used so that it is longitudinally parallel withthe axis of rotation of the rotating element of the shear cutter, thenit may be used in the aforesaid shape.

When, however, the die rule is to be used so that it extendslongitudinally around an arc of the cylinder about said axis of rotationthen the die rule is further formed into an arcuate shape to conform tothe curvature of such cylinder.

In order to bend the die rule into longitudinally arcuate shape, eachnotch 6 is formed of a suitable size and spacing to permit the bendingor forcing of adjacent legs 7 together for narrowing the mouth 8 of eachnotch 6 thereby to curve the cutting edge 2 of the strip 1 into thedesired arc. The step is performed by grasping the projecting leg 7between the notches 6 so as to put tension across the respective legs 7tending to close the gap of the notch 6 and directing the pointed flameof an oxyacetylene torch into the crotch 9 of the respective notch 6 soas to allow the crotch 9 to yield and the leg 7 to move to reduce themouth 8 of the notch 6, thereby to produce the desired curve on theouter cutting edge 2 of the die rule. These steps are repeatedsequentially, notch by not-ch along the base edge 3 until the finaldesired curve is achieved.

The legs 7 are bent out of the plane of the strip 1 alternately inopposite directions and, for further firming the securing grip, the baseend of each leg 7 is split or bifurcated so as to form a pair of prongs10 bent oppositely out of the plane of the leg 7.

The mounting means for the die rule includes a die rule holder base 11detachably secured to a second base 12 which latter adapted to besecured to the usual rotating element 13 of a rotary shear cutter.

The die rule holder base 11 in the herein illustrative embodiment is acurved or tubular piece of laminated Wood or plywood. The curvature ofthe holder base 11 is concentric with the cylinder around the axis ofrotation of the rotating element.

A series of slits 14 are cut through the holder base 11 so arranged thatthe pattern of the slits 14 defines substantially the contour of the dierule. The interrupting ribs 16 between the slits 14 are so located as tocorre spond to the adjacent notches 6 and thus permit the pressing ofthe legs 7 into the slits 14.

The slits 14 are cut perpendicular or at right angles to the axis ofrotation of the rotating element 13. The die rule pressed into the slits14, therefore, is also perpendicular or at right angles to said axis ofrotation. The notches 6 and legs 7 are about the same height as thethickness of the holder base 11 and the ruler strip 1 is wider than thethickness of the base 11, hence the cutting edge 2 of the die ruleprotrudes from the convex face of the curved holder base 11. In theherein illustration the slits are cut with a saw of about the samethickness as that of the metal strip 1 so as to assure tight fit and thedie rule legs 7 are forced into the respective slits as shown in FIG. 8.

1n the modified form shown in FIG. 9 a continuous slit, about thethickness of the metal strip 1, is cut through the holder base 11 so asto cut out a complete hole 16 conforming to the outline of the die rule.The above described die rule is then inserted into the hole and thecut-out plug 17 is driven into the inside of the die rule as the latteris positioned in the hole 16 so as to tightly wedge the die rule inplace.

The curved laminated wood base 11 has a plurality of holes 18therethrough to accommodate fastening screws 19 for fastening the holderbase 11 to the second base 12. This second base 12 is a metal platenalso curved concentrically about said axis of rotation and is secured tothe rotating element 13 by means of T bolts 21 and heads 22 of which areretained in the usual inverted T grooves 23 in the periphery of thecylindrical part of the rotating element 13. A usual nut 24 on the bolt21 mounts the metal second base 12 in place and provides firm support.

In order further to assure firmness and prevent creeping or even theslightest rocking of the laminated holder base 11 relatively to thesecond base 12, the concave face of the holder base is covered with aninitially cold fiowable plastic coating containing a setting orhardening agent and capable of fitting the minute clearance between theconcave face 26 of the holder base 11 and the adjacent convex face 27 ofthe second base 12. This is applied immediately before assembly so thatas the plastic hardens it shapes itself for filling all clearances andspaces.

In the herein illustrative embodiment a coating layer 28 of so calledepoxy is used. Before applying the epoxy layer 28, however, both theconvex face 27 of the second base 12 and bottom portion of the slits 14are coated with a silicon base wax or other suitable releasing agent tofacilitate disassembly when required, yet assure absolutely tightforming of the epoxy coating. The epoxy applied to the concave face 26of the holder base 11 fiows into the bottom portion of the slits 14 andaround the base edge 3 of the die rule so as to fill all minute spacearound the base of the die rule in the slit. The base portion of the dierule is also covered with said releasing agent to facilitate replacementand repair.

The die rules constructed and mounted in accordance with this inventionwork against the usual platens on the opposite rotating element of therotary shear cutter not shown. For instance the serrated edged die ruleworks against a rubber platen and the straight cutting edge worksagainst a metal platen.

I claim:

1. In a method of forming a die rule and die rule mounting for arotating die cutter element the steps of providing a primary baseconforming to the peripheral curvature of rotation of said element,

forming slits through said primary base conforming to the contour of thedie rule,

pressing the die rule into the slits so that the cutting edges of thedie rule protrude from the convex face of said primary base,

and mounting said primary base on a curved second base adapted to besecured to said rotating element. 2. The method defined in claim 1,wherein said primary base is made of wood,

and applying a fiowable material containing a hardening agent on theconcave face of said wood base to form a firm bedding between saidbases. 3. The method defined in claim 2 wherein said material is epoxy,

and coating the adjacent surfaces of said bases with an epoxy releasingagent prior to applying said epoxy so as to permit separation of thebases for replacement. 4. The method defined in claim 1, wherein saiddie rule is formed by the following steps,

cutting a series of spaced notches transversely into the base edge ofthe die rule, momentarily applying heat to the crotch of a notch, andforcing the metal adjacent said notch together so as to narrow the mouthof the notch, and repeating said heating and forcing steps on the seriesof notches until the die rule is bent to a desired curve conforming tothe curve of said primary base. 5. In the method defined in claim 1,wherein said die rule is formed of a strip of metal by the steps of,

forming a series of notches transversely into the base edge of thestrip, forming the strip into the shape of the cut, momentarily applyingheat to the crotch of a notch, forcing the metal adjacent said notchtogether so as to narrow the mouth of the notch, and repeating saidheating and forcing steps on the series of notches until the die rule isbent to a desired curve conforming to the curve of said primary base. 6.The method defined in claim 4, wherein said primary base is made ofwood,

coating the adjacent surfaces of the wood base and the second base witha fiowable material and hardening agent therefor to form a firm bed andso that part of said material flows into said slits. '7. The methoddefined in claim 4, wherein said primary base is made of wood,

coating the adjacent surfaces of the wood base and the second base witha flowable material and hardening agent therefor to form a firm bed andso that part of said material flows into said slits, and coating saidadjacent surfaces with a releasing agent before applying said firstcoating material so as to permit separation of said bases after thehardening of said mtaerial. 8. In a method of forming a die rule for therotating element of a rotary cutter device the steps of,

providing a metal strip with a longitudinal cutting edge and a baseedge, forming spaced series of notches transversely in the base edge ofsaid strip, bending the strip into the contour of the selected cut, andnarrowing the mouth of the notches, notch by notch while applying heatto the crotch of the respective notches in sequence until the die ruleis bent longitudinally into a curvature conforming to the correspondingarc of a circle about the axis of rotation of said rotating element. 9.In a die rule mounting for the rotating element of a die cutting device,

the combination with die rule formed of a strip of metal with alongitudinal cutting edge and an opposite base edge; of a primarymounting block of arcuate cross section conforming to part of a cylinderabout the axis of rotation of said rotating element, said primarymounting block having a series of longitudinally spaced slitstherethrough arranged in a pattern conforming substantially to thecontour of said die rule,

said die rule being notched so as to form legs therebetween fittingtightly into said slits,

and a base plate capable of being mounted on said rotary element,

and means to secure said block on said base plate.

10. The die rule mounting defined in claim 9, and

said mounting block being made of laminated wood, and a firm beddingbetween said block and said base plate,

said bedding being formed out of initially flowable plastic materialcontaining a hardening agent and extending around the base edge of saiddie rule in said slits.

11. The die rule mounting defined in claim 9, and

said mounting block being made of laminated Wood,

and a firm bedding between said block and said base plate,

said bedding being formed out of initially flowable plastic materialcontaining a hardening agent and extending around the base edge of saiddie rule in said slits,

and a coating of releasing agent between said bedding and said baseplate to facilitate removal of said block.

12. The invention defined in claim 9, and

the base edge having a series of notches therein,

legs formed between said notches being bent out of the plane of saidstrip alternately in opposite directions and converging toward saidplane and said cutting edge for tighter fitting into said slits,

and a pair of prongs formed in the base tip of each leg bent in oppositedirections laterally from the plane of the leg.

13. In a method of forming a die rule mounting for a rotating die cutterelement the steps of,

providing a primary base curved to conform to the peripheral curvatureof rotation of said element.

forming a die rule to the shape of the cut and bending the die rule toconform to the curvature of said primary base,

cutting a continuous slit through the primary base conforming to thecontour of said die rule and substantially of the same width as thethickness of the material of the die rule thereby cutting out a plugfrom said primary base,

positioning the preformed and prebent die dule in said slit,

forcing the plug severed by said slit into said die rule so as to holdsaid die rule in place,

and mounting said primary base on a curved second base adapted to besecured to said rotating element.

14. In a die rule mounting for the rotating element of a die cuttingdevice,

a primary mounting block of arcuate cross section conforming to a partof a cylinder about the axis of rotation of said rotating element,

a die rule formed of a strip of metal with a longitudinal cutting edgeand an opposite base edge preformed into the shape to be cut andpre-bent to the curvature of said arcuate cross section of said primarymounting block and positioned in said block,

said primary mounting block being made of laminated Wood and having acontinuous slit cut therethrough in the shape of said die rule and ofabout the width of the thickness of said die rule strip of metal,

and a plug formed by said continuous slit being driven into its originalposition within said continuous slit to hold said die rule in position.

15. In a method of forming a die rule and die rule mounting for arotating die cutter element and steps of providing a base conforming tothe peripheral curvature of rotation of said element,

forming slits through said base conforming to the contour of the dierule,

pressing the die rule into the slits so that the cutting edges of thethe rule protrude from the convex face of said base,

and morning said base on said rotating element.

16. The method defined in claim 15 wherein said base is made of wood.

17. In a die rule mounting for the rotating element of a die cuttingdevice,

the combination with a die rule formed of a strip of metal with alongitudinal cutting edge and an opposite base edge;

a mounting block of arcuate cross section conforming to part of acylinder about the axis of rotation of said rotating element,

said mounting block having slits therethrough arranged in a patternconforming substantially to the contour of said die rule,

said die rule being notched from its base edge inwardly so as to formlegs on said base edge between the notches fitting tightly into saidslits,

and means to secure said block to said rotating element.

18. In a die rule mounting for the rotating element of the die cuttingdevice, the combination with a die rule formed of a strip of metal witha longitudinal cutting edge and an opposite base edge of a mountingblock of laminated wood being arcuate to conform to part of a cylinderabout the axis of rotation of said rotating element,

said mounting block having slits therethrough arranger] in a patternconforming substantially to the contour of said die rnle;

said die rule being notched so as to form legs between the notchesfitting tightly into said slits,

and means to secure said block to said rotating element.

References Cited by the Examiner The following references, cited by theExaminer, are

of record in the patented file of this patent or the original WILLIAM W.DYER, 1a., Primary Examiner. WILLIAM S. LAWSON, Examiner. L. B. TAYLOR,Assistant Examiner.

